The present invention relates to angular velocity sensors, electronic apparatuses, and methods of detecting an angular velocity, which are used for shake detection on video cameras, motion detection on virtual reality apparatuses, and direction detection on car navigation systems, for example.
Oscillating gyro sensors are widely used as consumer-use angular velocity sensors. The oscillating gyro sensors cause an oscillator to oscillate at a predetermined frequency, and use a piezoelectric element or the like to sense Coriolis force generated on the oscillator to thereby detect an angular velocity. Such oscillating gyro sensors are installed in electronic apparatuses such as video cameras, virtual reality apparatuses, and car navigation systems, for use as sensors for shake detection, motion detection, and direction detection, respectively.
To detect posture changes in a space using this type of gyro sensors, there is a known arrangement in which the gyro sensors are disposed in the directions of two or three axes orthogonal to one another. For example, Patent Document 1 discloses an arrangement in which three gyroscopes have oscillators mounted on a flexible substrate and the flexible substrate is folded to make the three oscillators orthogonal to one another, thereby realizing three-dimensional angular velocity detection. Similarly, Patent Document 2 discloses a three-dimensional angular velocity sensor that is disposed on a base stand in such a manner that tripod tuning-fork oscillators are orthogonal to one another in the directions of three axes.
Patent Document 1: Japanese Patent Application Laid-open No. 11-211481 (paragraph [0017] and FIG. 1)
Patent Document 2: Japanese Patent Application Laid-open No. 2000-283765 (paragraph [0019] and FIG. 8)